Here is a link to a project on Indestructables.com where a Raspberry Pi Zero (RP) is wired into a TP420 ultrabay. The RP uses TP power and is accessed from the Thinkpad (running Win or Linux) via a VNC session.

Too bad the TP peripherals (keyboard, screen, etc.) can't be accessed and controlled directly from the RP in the ultrabay circumventing the conventional OS installed on the TP hardware. Might open the door to resurrecting older TPs with cutting edge single board computers, (RP3, Beagleboards, etc.).

Here is a link to a project on Indestructables.com where a Raspberry Pi Zero (RP) is wired into a TP420 ultrabay. The RP uses TP power and is accessed from the Thinkpad (running Win or Linux) via a VNC session.

Too bad the TP peripherals (keyboard, screen, etc.) can't be accessed and controlled directly from the RP in the ultrabay circumventing the conventional OS installed on the TP hardware. Might open the door to resurrecting older TPs with cutting edge single board computers, (RP3, Beagleboards, etc.).

For most displays that are used in laptops you can buy so called control boards, and as far as I understand it, they convert the panel's LVDS to HDMI, so that you can use it with the Pi.

I think the main problem is the keyboard and trackpoint. I remember reading about a couple of projects regarding them, but they seem to be abandoned now.

But I think you are right, it would be amazing to use these old thinkpads with a modern Pi variant inside them in the near future, when they will become hopelessly obsolete.

It looks pretty complicated, but I will have a more thorough read later. Looks like it's doable after all, the guy who wrote that article even made a standalone keyboard in a wooden case, using the Thinkpad T61 keyboard. Ireally do think that in the near future people will resurrect their old, dying thinkpads this way.